The present invention is directed to a ventilator for the window of an automobile or other motor vehicle, which ventilator is used while the vehicle is parked in order to prevent the interior of the vehicle from reaching very high temperatures. There are ventilators that are used for allowing for the interchange of air between the interior of an automobile and the ambient, in order to provide for a cooling effect via such air exchange. These prior-art ventilators are static vents in that the air exchange is allowed to be carried out without any external assistance, such static air vents relying upon the air currents created by the differences in temperature between the two air masses for the exchange of air, as well as upon air currents developed by wind and the concomitant pressure differentials associated therewith. Such static vents, however, provide only a limited degree of air exchange, and lower the interior temperature very little. The present invention is directed to a dynamic vent in which a fan or blower forces the air exchange to take place.